</excludePackageNames>
          <!-- Ignore some tags that are found in Java 11 sources but not recognized... under -source 8, I think it was? I can no longer reproduce the failure. -->
          <tags>
            <tag>
              <name>apiNote</name>
              <placement>X</placement>
            </tag>
            <tag>

          </excludePackageNames>
          <!-- Ignore some tags that are found in Java 11 sources but not recognized... under -source 8, I think it was? I can no longer reproduce the failure. -->
          <tags>
            <tag>
              <name>apiNote</name>
              <placement>X</placement>
            </tag>
            <tag>

        <jdk>1.8</jdk>
      </activation>
      <build>
        <plugins>
          <plugin>
            <artifactId>maven-compiler-plugin</artifactId>
            <configuration>
              <!-- Under JDK8, we continue to use errorprone's javac9 (even
                   though we don't run Error Prone itself, which no longer
                   supports JDK8!).

                   Why? At some point, presumably after

              <validateOnly>true</validateOnly>
              <sourceLevel>1.8</sourceLevel>
              <!--
                To avoid "java.io.IOException: User limit of inotify watches reached" under JDK10.
                Presumably we don't need inotify, since we don't intend to change files during the
                build?
                -->
              <extraJvmArgs>-Dgwt.watchFileChanges=false</extraJvmArgs>